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{{Short description|Genus of Kerymachelid lobopodian from the Middle Cambrian}}
{{Short description|Genus of kerygmachelid lobopodian from the Middle Cambrian}}
{{Italic title}}
{{Italic title}}
{{Use dmy dates|date=December 2023}}{{Use Australian English|date=December 2023}}
{{Use dmy dates|date=December 2023}}{{Use Australian English|date=December 2023}}
{{Automatic taxobox
{{Automatic taxobox
| fossil_range = <br/>[[Cambrian Stage 4]], {{fossil range|~514|~509}}
| fossil_range = <br/>[[Cambrian Stage 4]], {{fossil range|514|509}}
| image =
| image = Anomalocaris KUMIP 298510.jpg
| image_caption =
| image_caption = Fossil holotype
| image2 = 20231214 Mobulavermis adustus diagrammatic reconstruction.png
| image2_caption = Diagrammatic reconstruction
| taxon = Mobulavermis
| taxon = Mobulavermis
| authority = McCall, [[2023 in paleontology|2023]]
| authority = McCall, [[2023 in paleontology|2023]]
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}}
}}


'''''Mobulavermis''''' (meaning "Mobula worm") is an extinct genus of [[Kerygmachelidae|kerygmachelid]] [[lobopodian]] from the [[Combined Metals Member]] of the [[Pioche Formation]] in [[Nevada]]; [[USA]]. The type species is '''''M'''''. '''''adustus''''', known from the [[holotype]] and [[paratype]].<ref name="McCall2023">{{cite journal |last1=McCall |first1=Christian |title=A large pelagic lobopodian from the Cambrian Pioche Shale of Nevada |journal=Journal of Paleontology |date=13 December 2023 |doi=10.1017/jpa.2023.63 |url=https://www.cambridge.org/core/journals/journal-of-paleontology/article/abs/large-pelagic-lobopodian-from-the-cambrian-pioche-shale-of-nevada/11B0704C49A7730AA3E8F46EB2CA1C95?utm_campaign=shareaholic&utm_medium=copy_link&utm_source=bookmark#article |access-date=13 December 2023}}</ref>
'''''Mobulavermis''''' ({{IPA-all|ˌmɒbjuləˈuɛrmɪs}}) (meaning "Mobula worm") is an extinct genus of [[Cambrian]] [[Kerygmachelidae|kerygmachelid]] [[lobopodian]] from the [[Pioche Shale]], the [[Combined Metals Member]] of the [[Pioche Formation]] in [[Nevada]]; [[USA]]. The type species is '''''M. adustus''''', known from the [[holotype]] and [[paratype]].<ref name="McCall2023">{{cite journal |last1=McCall |first1=Christian |title=A large pelagic lobopodian from the Cambrian Pioche Shale of Nevada |journal=Journal of Paleontology |date=13 December 2023 |volume=97 |issue=5 |pages=1009–1024 |doi=10.1017/jpa.2023.63 |bibcode=2023JPal...97.1009M |url=https://www.cambridge.org/core/journals/journal-of-paleontology/article/abs/large-pelagic-lobopodian-from-the-cambrian-pioche-shale-of-nevada/11B0704C49A7730AA3E8F46EB2CA1C95 |access-date=13 December 2023}}</ref>

== Etymology ==
The generic name, ''Mobulavermis'' ({{IPA-all|ˌmɒbjuləˈuɛrmɪs}}) comes from ''[[Mobula]]'', the genus name of extant [[manta rays]] and [[Mobula|devil rays]]. This draws comparison to the elongate flexible caudal spines and broad swimming flaps of ''Mobula'' rays, which resemble the outline of the new taxon. This is combined with the [[Latin Language|Latin]] 'vermis', which translates to "worm". The specific name, ''adustus'' ({{IPA-all|ˌaduˈstʊs}}) is a Latin word which can mean "burnt", "singed", or "sun-burnt". This is in reference to the dramatic yellow, red, and black coloration of the two known specimens, and to the arid conditions of the type locality.<ref name="McCall2023"/>


== Description ==
== Description ==
[[File:Mobulavermis adustus.png|thumb|left|Life reconstruction with speculative head region based on ''[[Kerygmachela]]'']]
''Mobulavermis'' is known from two specimens which were described in 2023 by McCall, (2023). The holotype, '''KUMIP 298510''', measures at around {{convert|80.60|mm|inch|1|abbr=on|sp=us}}, and preserves the posterior portion of the body. And the paratype,'''KUMIP 298511''', measures at around ~{{convert|50.7|mm|inch|1|abbr=on|sp=us}} along the [[saggital]] curve of the trunk, and is also an incomplete individual which preserves the posterior portion of the body.<ref name="McCall2023"/>
''Mobulavermis'' is known from two specimens which were described by McCall, (2023). The intact posterior region of the holotype, '''KUMIP 298510''', measures around {{convert|80.60|mm|inch|1|abbr=on|sp=us}} down the curve of the body. The paratype, '''KUMIP 298511''', measures roughly ~{{convert|50.7|mm|inch|1|abbr=on|sp=us}} along the [[sagittal]] curve of the trunk, and is also an incomplete individual which preserves the posterior portion of the body, although traces of the trunk and flaps continue towards the anterior.<ref name="McCall2023" />


The trunk is unsclerotized, and lined with fine transverse annulations. A circular structure occurs beside the gut in the holotype - this may represent a digestive gland. It is described as having more lateral flaps than any other known lobopodian or [[Radiodonta|radiodont]]; at least 18 down the length of the trunk, becoming smaller towards the caudal spine in an acuminate distribution. The posterior margins of the flaps are smooth and round, while the anterior margins appear flatter. The flaps were perhaps only weakly textured, in comparison to the wrinkled flaps of ''[[Kerygmachela]]''. The caudal spine transitions smoothly from the trunk portion, apparently shorter and flexible than those of ''Kerygmachela''.<ref name="McCall2023" />
== Etymology ==

The generic name, ''Mobulavermis'' comes from '[[Mobula|''Mobula'']]', the genus name of extant [[manta rays]] and [[devil ray|devil rays]]. This draws comparison to the elongate flexible caudal spines and broad swimming flaps of ''Mobula'' rays, which resemble the outline of the new taxon. This is combined with the [[Latin Language|Latin]] 'vermis', which translates to "worm". The specific name, ''adustus'' is a Latin word which can mean "burnt", "singed", or "sun-burnt". This is in reference to the dramatic yellow, red, and black coloration of the two known specimens, and to the arid conditions of the type locality.<ref name="McCall2023"/>
Adult individuals may have reached between ~{{convert|30|cm|inch|1|abbr=on|sp=us}} and ~{{convert|50|cm|inch|1|abbr=on|sp=us}}, based on complete specimens of ''Kerygmachela'', making it large among Cambrian animals. It is thought to have been [[pelagic]], feeding on small prey in the water column, with elongate [[compound eyes]] on the underside of the head, also inferred from ''Kerygmachela''.<ref name="McCall2023" />

== Classification ==
[[File:20191022 Kerygmachela kierkegaardi without lobopods.png|thumb|right|Reconstruction of ''Kerygmachela kierkegaardi'', a close relative of ''Mobulavermis'', following McCall (2023).<ref name="McCall2023"/>]]
In his [[phylogenetic]] analysis, McCall, (2023) recovered ''Mobulavermis'' amongst the "gilled lobopodians" (''[[Utahnax]]'', and ''[[Kerygmachela]]''). The paper also finds that "gilled lobopodians" form a [[monophyletic]] clade, [[Kerygmachelidae]], which is also erected in the same paper, although had been used informally to refer to the group in lieu of an established clade name.<ref>{{Cite journal |last1=Moysiuk |first1=Joseph |last2=Caron |first2=Jean-Bernard |date=2022-07-08 |title=A three-eyed radiodont with fossilized neuroanatomy informs the origin of the arthropod head and segmentation |journal=Current Biology |volume=32 |issue=15 |pages=3302–3316.e2 |language=en |doi=10.1016/j.cub.2022.06.027 |pmid=35809569 |s2cid=250361698 |issn=0960-9822|doi-access=free |bibcode=2022CBio...32E3302M }}</ref> Previously, it had been suggested that ''Kerygmachela'' and ''Utahnax'' may have evolved their lateral flaps [[Convergent evolution|independently]] from radiodonts, opabiniids, and ''[[Pambdelurion]]'' through a flattening of the walking lobopods of its ancestors, and that the lobopod limbs of ''Kerygmachela'' had been insufficiently demonstrated.<ref>{{Cite journal |last1=Lerosey-Aubril |first1=Rudy |last2=Ortega-Hernández |first2=Javier |date=2022 |editor-last=Zhang |editor-first=Xi-Guang |title=A new lobopodian from the middle Cambrian of Utah: did swimming body flaps convergently evolve in stem-group arthropods? |url=https://onlinelibrary.wiley.com/doi/10.1002/spp2.1450 |journal=Papers in Palaeontology |language=en |volume=8 |issue=3 |doi=10.1002/spp2.1450 |bibcode=2022PPal....8E1450L |s2cid=250076505 |issn=2056-2799}}</ref> The description of a new kerygmachelid that clearly lacked lobopodous legs appears to have confirmed this hypothesis. The following [[cladogram]] represents the phylogenetic results of a 50% majority rule consensus tree.<ref name="McCall2023"/>

{{clade|style=font-size:90%;line-height:90%
|label1=[[Euarthropoda|Total-group Euarthropoda]]
|1={{clade
|1='''[[Lobopodia#Siberion_and_similar_taxa|Siberiidae]]'''
|2={{clade
|label1=[[Kerygmachelidae]]
|1={{clade
|1=''[[Utahnax]]''
|2={{clade
|1='''''Mobulavermis'''''
|2=''[[Kerygmachela]]''
}} }}
|2={{clade
|1={{clade
|1=''[[Omnidens]]''
|2=''[[Pambdelurion]]''
}}
|2={{clade
|1='''[[Opabiniidae]]'''
|2={{clade
|1=''[[Caryosyntrips]]''
|2={{clade
|1={{clade
|1='''[[Radiodonta]]'''
|2='''[[Deuteropoda]]'''
}} }} }} }} }} }} }} }}


== References ==
== References ==
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{{Dinocaridida}}
{{Dinocaridida}}
{{Portalbar|Paleontology|Cambrian|USA}}
{{Portal bar|Paleontology|USA}}


{{Taxonbar|from=Q121769013}}
{{Taxonbar|from=Q121769013}}
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[[Category:Taxa described in 2023]]
[[Category:Taxa described in 2023]]
[[Category:Fossil taxa described in 2023]]
[[Category:Fossil taxa described in 2023]]
[[Category:Cambrian Nevada]]

Latest revision as of 17:33, 25 December 2024

Mobulavermis
Temporal range:
Cambrian Stage 4, 514–509 Ma
Fossil holotype
Diagrammatic reconstruction
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Family: Kerygmachelidae
Genus: Mobulavermis
McCall, 2023
Type species
Mobulavermis adustus
Christian R. A. McCall, 2023

Mobulavermis (IPA: [ˌmɒbjuləˈuɛrmɪs]) (meaning "Mobula worm") is an extinct genus of Cambrian kerygmachelid lobopodian from the Pioche Shale, the Combined Metals Member of the Pioche Formation in Nevada; USA. The type species is M. adustus, known from the holotype and paratype.[1]

Etymology

[edit]

The generic name, Mobulavermis (IPA: [ˌmɒbjuləˈuɛrmɪs]) comes from Mobula, the genus name of extant manta rays and devil rays. This draws comparison to the elongate flexible caudal spines and broad swimming flaps of Mobula rays, which resemble the outline of the new taxon. This is combined with the Latin 'vermis', which translates to "worm". The specific name, adustus (IPA: [ˌaduˈstʊs]) is a Latin word which can mean "burnt", "singed", or "sun-burnt". This is in reference to the dramatic yellow, red, and black coloration of the two known specimens, and to the arid conditions of the type locality.[1]

Description

[edit]
Life reconstruction with speculative head region based on Kerygmachela

Mobulavermis is known from two specimens which were described by McCall, (2023). The intact posterior region of the holotype, KUMIP 298510, measures around 80.60 mm (3.2 in) down the curve of the body. The paratype, KUMIP 298511, measures roughly ~50.7 mm (2.0 in) along the sagittal curve of the trunk, and is also an incomplete individual which preserves the posterior portion of the body, although traces of the trunk and flaps continue towards the anterior.[1]

The trunk is unsclerotized, and lined with fine transverse annulations. A circular structure occurs beside the gut in the holotype - this may represent a digestive gland. It is described as having more lateral flaps than any other known lobopodian or radiodont; at least 18 down the length of the trunk, becoming smaller towards the caudal spine in an acuminate distribution. The posterior margins of the flaps are smooth and round, while the anterior margins appear flatter. The flaps were perhaps only weakly textured, in comparison to the wrinkled flaps of Kerygmachela. The caudal spine transitions smoothly from the trunk portion, apparently shorter and flexible than those of Kerygmachela.[1]

Adult individuals may have reached between ~30 cm (11.8 in) and ~50 cm (19.7 in), based on complete specimens of Kerygmachela, making it large among Cambrian animals. It is thought to have been pelagic, feeding on small prey in the water column, with elongate compound eyes on the underside of the head, also inferred from Kerygmachela.[1]

Classification

[edit]
Reconstruction of Kerygmachela kierkegaardi, a close relative of Mobulavermis, following McCall (2023).[1]

In his phylogenetic analysis, McCall, (2023) recovered Mobulavermis amongst the "gilled lobopodians" (Utahnax, and Kerygmachela). The paper also finds that "gilled lobopodians" form a monophyletic clade, Kerygmachelidae, which is also erected in the same paper, although had been used informally to refer to the group in lieu of an established clade name.[2] Previously, it had been suggested that Kerygmachela and Utahnax may have evolved their lateral flaps independently from radiodonts, opabiniids, and Pambdelurion through a flattening of the walking lobopods of its ancestors, and that the lobopod limbs of Kerygmachela had been insufficiently demonstrated.[3] The description of a new kerygmachelid that clearly lacked lobopodous legs appears to have confirmed this hypothesis. The following cladogram represents the phylogenetic results of a 50% majority rule consensus tree.[1]

Total-group Euarthropoda

References

[edit]
  1. ^ a b c d e f g McCall, Christian (13 December 2023). "A large pelagic lobopodian from the Cambrian Pioche Shale of Nevada". Journal of Paleontology. 97 (5): 1009–1024. Bibcode:2023JPal...97.1009M. doi:10.1017/jpa.2023.63. Retrieved 13 December 2023.
  2. ^ Moysiuk, Joseph; Caron, Jean-Bernard (8 July 2022). "A three-eyed radiodont with fossilized neuroanatomy informs the origin of the arthropod head and segmentation". Current Biology. 32 (15): 3302–3316.e2. Bibcode:2022CBio...32E3302M. doi:10.1016/j.cub.2022.06.027. ISSN 0960-9822. PMID 35809569. S2CID 250361698.
  3. ^ Lerosey-Aubril, Rudy; Ortega-Hernández, Javier (2022). Zhang, Xi-Guang (ed.). "A new lobopodian from the middle Cambrian of Utah: did swimming body flaps convergently evolve in stem-group arthropods?". Papers in Palaeontology. 8 (3). Bibcode:2022PPal....8E1450L. doi:10.1002/spp2.1450. ISSN 2056-2799. S2CID 250076505.